Various synthetic sulfonylurea compounds having herbicidal actions have been reported in Japanese Patent Application Laid Open Nos. 162587/1983 and 45572/1985, and European Patent Application Laid Open Nos. 96003, 52286 and 238,070. Several compounds are commercially available as herbicides for cereal areas (Glean.TM., Ally.TM., Harmony.TM., Amber.TM., etc.).
Although such sulfonylurea compounds exert potent herbicidal actions on broadleaf weeds in an extremely low concentration, they are still unsatisfactory in practical use because of drawbacks including either no or only weak herbicidal activity against graminaceous weeds in wheat fields under a selective use.
Therefore, it has been desired to develop a herbicide having a satisfying herbicidal activity against graminaceous weeds and no adverse effect such as damage of small grain cereals from the herbicide.